Development of Terahertz Surface Plasmonic Sensor Based on Metal–Insulator Composite Woven-Wire Mesh

Borwen You^1*, Chi-Hua Tsai², Ping-Yen Chuang¹, Hung-Yi Tsai¹, Po-Lun Chen², Ja-Yu Lu²

¹Department of Physics, National Changhua University of Education, Changhua City, Taiwan
²Department of Photonics, National Cheng Kung University, Tainan city, Taiwan

* Presenter:Borwen You, email:borwenyou@cc.ncue.edu.tw

Surface plasmonic sensors in terahertz (THz) frequency range are experimentally demonstrated on the metal surface of polyethylene terephthalate wire woven meshes, calling the metal-insulator composite woven-wire mesh (MCWM). The PET mesh substrate not only has approximately free THz wave loss but also provides the cavities of periodically corrugated wires on the metal surface. MCWM-based plasmonic sensors in this study further integrate THz time-domain spectroscopy to sense different types and quantities of analytes, including hydrophilic biopolymer (PAA) membrane, nonuniformly distributed microparticles to mimic macro-biomolecules or cells, and electrolyte salts of PBS. MCWM sensors perform the best thickness and refractive index sensitivities approaching 8.26 GHz/μm and 547 GHz/RIU, respectively, which can compete those molecular sensors in the infrared ray spectrum. The MCWM-based sensing platform presents a rapid, inexpensive, and simple analysis method, potentially paving the way for a new generation of label-free microanalysis sensors.

Keywords: Terahertz wave, Spectroscopy, Surface plasmonic resonator, Optic sensor, Periodic metal structure